To order the activities from the greatest to least impact in reducing consumption of fossil fuels, we should consider which method of transportation has the least carbon footprint:
- Walk to work - This has the least impact on fossil fuel consumption since it does not involve any fuel use.
- Carpool to work - This option reduces the number of vehicles on the road, thus lowering overall fossil fuel consumption compared to driving alone.
- Drive an electric car to work - While electric cars are more environmentally friendly than traditional fossil fuel cars, they still have an impact depending on how the electricity is sourced (i.e., if it's from fossil fuels).
- Drive alone to work - This has the greatest impact on fossil fuel consumption since it involves using a vehicle that typically runs on gasoline or diesel.
Given this reasoning, the correct order from greatest to least impact to reduce fossil fuel consumption would be:
walk to work, carpool to work, drive an electric car to work.
So, the correct response is: walk to work, carpool to work, drive alone to work.